Over the years, the sport of bowling has been enjoyed by those exhibiting various degrees of skill. In fact, it often seems that the game is enjoyed equally as well by the novice as the professional. While the professional or more serious bowler is more aware of the variables which effect the game, the goals shared by all of these individuals is to improve their game score.
When seeking to improve ones game, the most commonly altered piece of equipment is, of course, the bowling ball. A sample of the choices which the bowler must make include whether or not the ball should be made of plastic, urethane or rubber, whether the grip should be drilled with deep finger holes or for a finger tip grip, and of course, one must also choose the weight of the ball which generally ranges from 8 to 16 lbs. Another variable which was noted in the early years of bowling was that the weight removed from the ball when drilling the finger holes affected the movement of the ball. This has led some bowlers to add weights near the finger holes in order to offset the loss due to drilling while others have added weights in specific locations in order to cause an imbalance and thereby alter the movement of the ball.
While we were studying the various effects produced by different weight distributions, a number of professional bowlers were questioned concerning their experiences. Quite surprisingly, we found their answers to be significantly different from one another. The reason for this discrepancy appears to be twofold. First, the effect of a weight imbalance will depend somewhat upon the degree of lift as well as the ball's direction during delivery which varies from bowler to bowler. Secondly, since there has not been a suitably effective way to test the various bowling ball weight combinations, conclusions as to the various effects of weight imbalances are often based upon an inadequate amount of data.
Prior to this invention, one wishing to test various weight imbalances either had to have his bowling ball drilled and replugged with different weights, or else purchase a large number of bowling balls and have each one drilled and weighted separately. The first option was found to be impractical because it required too much time which prevented accurate comparisons of the various weight imbalances under the same conditions. The latter solution was also found to be impractical due to the cost of purchasing the large number of bowling balls that were required even if one were only to test the most basic weight variations.
For these reasons, it was an object of this invention to develop a bowling ball which could be used to experiment with a variety of weight combinations.
Another object of this invention was to provide a bowling ball with multiple weight distributions which was inexpensive to manufacture and easy to use.
Briefly described, the present invention is a bowling ball which contains a plurality of weight receptacles. If one were to imagine mutually perpendicular X, Y, and Z axes emanating from the center of the ball, then there would be a weight receptacle placed at the intersection of each axis and the external surface of the ball. Each receptacle is internally threaded to receive an insert of predetermined weight.
Also briefly described, the present invention is a method for manufacturing a bowling ball which is adapted to receive a plurality of weights in order to vary the balance of the ball. The first step involves drilling a number of weight receptacles. These receptacles are placed at the intersection of the ball's surface and the X, Y, or Z axes emanating from the center of the ball. The receptacle is then lined with an internally threaded cylinder and inserts of predetermined weight are placed therein.
Also briefly described, the present invention is a kit for modifying a standard bowling ball to receive a plurality of weighted inserts. The kit consists of a plurality of threaded weights and a number of weight cylinders made of poly-vinyl-chloride to be positioned in the weight receptacles which are drilled in the ball.